Due to important role of the metals in physiological and biosynthetic processes as modulators and constituents of enzyme systems, this study is focused on the action of iron(III) 3-oxotrinuclear compounds of the composition [Fe3O(AMA)(H2O)3]NO33H2O, where AMA: glycine (1), -alanine (2) [1, 2] on the synthesis of chlorophyll pigments of Dunaliella salina CNMN-AV-01 strain compared to total carotenoids from the microalgal biomass. The studied microalga was grow on organo-mineral medium prepared using the Spirulina platensis cultural liquid. The obtained results show an increase of the chlorophyll a/chlorophyll b ratio under the influence of Fe(III) coordination compounds with glycine/- alanine compared to control (grown in the standard conditions, in absence of coordination compound) (figure). Also, was noticed the increase of chlorophyll a content compared to chlorophyll b, along with the increase of coordination compounds concentration from 1 to 10 mg/L. In both cases, the highest values were obtained at supplementation of 10mg/L compound. The chlorophylls quantities are also equivalent for studied compounds (chlorophyll a/chlorophyll b ratio = 4.93 for 10 mg/L compound). Same proportional values are observed for other concentrations of 1 and 2. The total chlorophyll/carotenoids ratio decreases more obviously with the increase of 1 and 2 concentrations. The lowest values were observed at a maximum applied concentration (10 mg/L). Thus, the supplementation of investigated coordination compounds in nutritive medium (with the increase of concentration), as well as the increase in concentration of these compounds, altogether lead to the increase of the amount of D. salina carotenoids from the biomass, while the total chlorophyll content decreases. The presented research confirms previous studies which showed the carotenogenesis effect of Fe (III) coordination compounds on Dunaliella salina grown on different nutritive media [3]. Although the stimulatory action of studied coordination compounds on chlorophyll a/b ratio is observed (figure), the carotenogenesis effect is more pronounced, and increases with the increase of the compounds concentration. This carotenogenesis property of Dunaliella sp. is widely exploited, showing multiple benefits in humans and animals. They represent highly effective natural antioxidants, and in the interaction with chlorophyll pigments, the Dunaliella sp. biomass enhances the elimination of body toxic agents, adjusting the haematopoiesis by stimulating the biosynthesis of hemoglobin [4, 5].